SEOUL, SEPT. 11 -- The president of South Korea's opposition party said today that many Koreans will view a meeting between President Reagan and ruling party chairman Roh Tae Woo next week as "a sign of continuing support for the military government."

Kim Young Sam, one of two leaders likely to head the opposition in a presidential election in December, said he believes a White House meeting with Roh, who will be the ruling party candidate, will be widely criticized here. Roh is planning a Washington visit beginning Sunday and he is scheduled to meet with Reagan Monday morning, according to the White House.

"The people in this country have great reservations about Roh's trip to the United States," Kim said in an interview. "It's up to him whether he wants to visit the United States or anywhere else, but if President Reagan meets with Roh Tae Woo, many people would believe this is a sign of continuing support for the military government.

"People are very sensitive about a meeting with a candidate just prior to the election," Kim added.

{State Department spokesman Charles Redman today repeated the U.S. position that the United States will not support any candidate, but only the democratic process, in South Korea. Asked whether opposition figures would get the "same treatment" if they visited Washington, Redman said, "We would welcome visits by figures of either camp."}

Some officials at the U.S. Embassy here, who were not involved in planning Roh's visit, were said to believe that a White House meeting will make it more difficult for them to persuade already skeptical South Koreans of U.S. neutrality.

Ruling party officials have said that they hope a trip to the United States, and especially a White House meeting, will raise Roh's stature here before the election and give him the aura of a man with foreign policy experience.

Roh told a group of labor leaders here today that he will use the trip to explain the democratization process now under way and to assure U.S. leaders that there will be a peaceful transfer of power, the first in the republic's 40-year history.

Some political analysts here believe Roh's trip to the United States will give him a boost, helping to erase his image as a former general who assisted President Chun Doo Hwan in his 1980 military coup. Others, however, said it will help only among conservative, older Koreans who would vote for Roh anyway, while younger, more nationalist Koreans will resent his apparent seeking of U.S. support.

Kim Young Sam said many young people, with their increasing anti-Americanism, would not approve of the visit, but he said pro-American older Koreans might resent it as well.

"The younger generation will feel very antagonistic toward his visit because it would indicate that the American government still supports the dictatorship," he said. "Older people may feel Roh is using the visit for political propaganda."

In his interview, Kim again urged his rival opposition leader Kim Dae Jung to agree soon on which man will represent the opposition in December. Kim Young Sam also implicitly criticized Kim Dae Jung's recent triumphal tour through his home province when he said that he has resisted many calls from his supporters to visit his home area.

"It would be widely misinterpreted by people here as promoting regionalism, which would be very dangerous for our party," Kim said. "I will not visit my hometown or any other area until we have one candidate."

Kim Dae Jung comes from the southwestern province of Cholla, whose residents have been largely excluded from power for decades, while Kim Young Sam comes from the more populous southeastern province of Kyongsang. Although there is no ethnic separation and little difference in dialect, the regional rivalries are bitter and longstanding.